In new construction, electrical boxes are attached to supports prior to installing the surrounding wall or ceiling. Many electrical boxes are adapted to be attached to a joist, truss or other framing member. Wiring is run to the electrical box and housed within the electrical box. Once the electrical box is secured to the framing member and wired, the surrounding ceiling or wall is formed of drywall and painted. A tool, such as a drywall saw, is then used to cut an opening in the ceiling or wall proximate the electrical box. Then, an electrical fixture, such as a ceiling fan or luminary fixture, is attached to the electrical box.
In some instances, electrical boxes used to support electrical fixtures are the same depth as the depth of the drywall forming the finished surface. In other words, the thickness of the box enables the box to be flush with the finished surface upon installation. One-half inch drywall is the most popular ceiling or wall covering. Consequently, typical electrical boxes have a depth of one-half inch. However, there are cases where the thickness of the drywall must be varied in order to act as a sound barrier or to satisfy building code regulations for fire protection (e.g. hotels, apartments, etc.). In these cases, installers are limited to using products that are specific to the drywall thickness, or a product that can be extended.
Most electrical boxes do not have ways for easily extending or modifying their depth for use with varying ceiling or wall thicknesses. For example, U.S. Pat. No. 4,927,039 to McNab discloses an extender for an electrical box having bores in corner blocks of the extender for receiving fasteners to secure the extender to holes in the electrical box. U.S. Pat. No. 5,975,323 to Turan discloses an adjustable extender for an electrical box having spacers positioned between the extender and the electrical box to adjust the depth added to electrical box. U.S. Pat. No. 2,378,861 to Peevey and U.S. Pat. No. 2,989,206 to McAfee disclose outlet box extensions having removable scored sections to adjust the depth added to the electrical box. Fasteners secure the extension to the electrical box. Lastly, U.S. Published Patent Application Nos. 2003/0189043 to Wegner et al. and 2004/0051648 to Hagarty et al. disclose electrical box extensions that are secured to an outer surface of the electrical box with fasteners.
These patents and applications are directed to extensions intended for use primarily with fasteners. Moreover, these patents do not readily simplify the extension of an electrical box.
Thus, there is a continuing need to provide improved electrical box assemblies.